Fltte



M ay 4 1926.

w. F. STEWART FLUE "Filed ont. 13. 1925 Patented May 4, 1926.

UNITED STATES WILLIAM F. STEWAET, OF ST. LOUIS, MISSOURI.

FL'UE.

Application filed October 13, 1923. Serial No. 668,277.

To all 'whom z? may concern Y Be it known that I, W'ILLIAM F. STEWART,

a citizen of the United States, and a resident of the city of St. Louis and Stateof Missouri, have invented a new and useful Improvement in Fluss, of which the following is a specification.

My invention relates to flues, and particularly to the flues of gas water heaters and the like; and it has for its principal objects to prevent down drafts, and to admit cool air into the flue to prevent excessive draft. The invention consists principally in a flue having spaced circumferential openings therethrough and tongues projecting from the bottoms of said openings. The invention furthe-r consists in the parts yand combination of parts hereinafter described and claimed. v n zo In the accompanying drawing, Fig. l is an elevation of a flue embodying' my invention, Fig. 2 is a top plan view of the flue, and I? ig. 3 is a sectional view of the line 3 3 of Fig. 1.

Attached to the top of the casing 1 of a gas Water heater or the like is a fiue 2 that is preferably made of thin metal. Such flucs I are commonly subject to dov/n dra-ft that is likely to extinguish the pilot light of the heater and interfere with the heating of the Water. Likewise, when the heater is burning With a full iow of gas, the draft becomes excessive, and it is desirable to check it by admitting cool air to the flue.

According to my invention, portions are partly punched out of the flue to provide more or less triangular tongues 3 Whose bases are secured to the flue. These tongnes are bent inwardly; so that, looking at the flue from the top, they seem to close almost the entire cross-sectional area thereof. Thus, any down draft will be deflected by one or more of the tongues, and Will not be able to reach the flame or the pilot light.

In order to prevent the tongues from unduly checking the draft, I prefer to arrange them in a more or less helical series as shown most clearly in Fig. l. By this arrangement, the cross-sectional area of the iiue is not un- EAD duly reduced at any one point, and the draft is not choked. As the flame burns higher and higher in the operation o-f the Water heater, more and more air Will be drawn into the flue, and Will serve. to prevent the draft from becoming excessive. The tongues 'may be bent to any desired angle, and more tongues may be provided than are shown in the drawing, if required.

The abo-ve described flue prevents dovvn draft and admits a supply of air to the flue that Will prevent excessive draft, both of which are very desirable features for tlues of gas Water heaters and the like.

Obviously, numerous changes may be .made Without departing from my invention, and I do not Wish to be limited to the precise construction shown.l

IVhat I claim is:

l. A flue for gas Water heaters and the like having openings therethrough arranged in substantially helical series and inwardly bendable tongues at the bottoms of said openings.

2. A flue for gas Water heaters and the like having openings therethrough, and tongues projecting from the bottoms of said openings, said openings being spaced apart circumferentially. I

3. A flue for gas Water heaters and the like provided with openings therethrough, said openings being arranged in substantially helical series, and tongues projecting inwardly from the bottoms of said openings.

4i. A iiue for gas Waters heaters and the like provided with openings therethrough, said openings being spaced apart circumferentially andv arranged in substantially helical series, and tongues projecting inwardly from the bottoms of said openings.

5. A flue for gas Water heaters and the like having openings punched theretlnougli, and bendable tongues projecting inwardly `from the bot-toms of said openings, said openings being spaced apart circumferen` tially.

day of October, 1923.

WILLIAM F. STEWART.

Signed at St. Louis, Missouri, this 11th 

